基于无监督学习和注意力机制的水下偏振图像融合

Underwater polarization image fusion based on unsupervised learning and attention mechanisms

针对光线在水体中传播会受到吸收和散射影响,仅使用传统的强度相机获取水下图像存在成像结果亮度偏低、图像模糊、细节丢失等问题,将深度融合网络应用于水下偏振图像,即用深度学习的方法将水下偏振度图像与光强图像融合。分析水下主动偏振成像模型,搭建实验装置获取水下偏振图像构建训练数据集,并进行适当变换以扩充数据集。构建基于无监督学习和注意力机制引导的用于融合偏振度和光强图像的端到端学习框架,并对损失函数及权重参数进行阐述。使用制作的数据集在不同的损失权重参数下进行网络训练,基于不同的图像评价指标对融合后的图像进行评估。实验结果表明,融合后的水下图像细节更为丰富,相比于光强图像信息熵提升24.48%,标准差提升139%。相比于其他传统融合算法,该方法不需要人工调节权重参数,运算速度较快,具有较强的稳定性和自适应性,对于海洋探测、水下目标识别等领域的应用研究具有重要意义。

As light propagation in water is subject to absorption and scattering effects,acquiring underwa⁃ter images using conventional intensity cameras can result in low brightness of imaging results,blurred im⁃ages,and loss of details.In this study,a deep fusion network was applied to underwater polarimetric imag⁃es;the underwater polarimetric images were fused with light-intensity images using deep learning.First,the underwater active polarization imaging model was analyzed,an experimental setup was built to obtain underwater polarization images to construct a training dataset,and appropriate transformations were per⁃formed to expand the dataset.Second,an end-to-end learning framework was constructed based on unsu⁃pervised learning and guided by attention mechanism for fusing polarimetric and light intensity images and the loss function and weight parameters were elaborated.Finally,the produced dataset was used to train the network under different loss weight parameters and the fused images were evaluated based on different image evaluation metrics.The experimental results show that the fused underwater images are more de⁃tailed,with 24.48%higher information entropy and 139%higher standard deviation than light-intensity images.Unlike other traditional fusion algorithms,the method does not require manual weight parameter adjustment,has faster operation speed,strong robustness,and self-adaptability,which is important for ocean detection and underwater target recognition.